Study on the Potential of Raceway Pond Reactors in the Degradation of Pollutants in Aqueous Solution via Solar-Assisted Photo-Fenton Processes

This study investigates the potential of Fenton processes for phenol degradation, focusing on using a Raceway Pond Reactor. Initially, the effect of relevant variables (pH, nature of the complexant and Fe:L molar ratio) was evaluated by a 23 factorial design, using a conventional bench-scale reactor and radiation provided by a 5 W light emitting diode (LED) lamp. Higher degradation efficiency was observed in processes involving complexation with oxalate (1:1) and pH 7. Under these conditions, phenol degradation occurred rapidly, allowing almost complete removal in 2 min of treatment. A bench-scale Raceway Pond Reactor with a 10 L capacity was employed to assess processes assisted by solar radiation. In this system, high phenol degradation efficiency was observed in processes mediated by Fe-oxalate complexes at ratios of 1:1 and 1:3, achieving nearly complete removal of the model substrate within approximately 5 min of treatment. Under these conditions, peroxide consumption occurred quickly (approximately 80% in 15 min), which made it necessary to add a second dose within 20 min. These findings highlight the strong potential of the system for treating emerging pollutants in aqueous solutions, such as effluents from sewage treatment plants.